li.selected{
    background-color: red;
    color: white;
}
a{
    background-color: green;
    display: inline-block;
    width: 80px;
    height: 30px;
    line-height: 30px;
    text-decoration:none;
    color: white;
    font-size: 20px;
    font-family: "时尚简黑中体";
    text-align: center;
    margin: 10px;
    
}